I have no objection to Catholicism identifying sodomy as a sin. I'm not Catholic, and it's a mistake for an outsider to critique religious doctrines on the grounds that they insufficiently resemble the principles of a liberal democratic state. On the other hand, the religious basis for a set of political views provides no immunity against their being criticized by non-believers, and indeed invites a new line of inquiry as to whether the line between the civic and the religious is being maintained in the right place and the right way. It's not bigotry to remind a politician of the truth Eugene's been emphasizing in his Ten Commandment posts-- that it's also a mistake to treat the internal doctrines of one's religion as sufficient reason for legislation and coercion, that it's a mistake to criticize the liberal democratic state for insufficiently resembling one's own church.
Of course the "doctrine of the liberal democratic state" is also not a sufficient reason for legislation and coercion. Those who object to the imposition of religious doctrine on the heathen have a point. But they lose that point when they choose to impose their legal regime on non-believers (the faithful).
So if you want persons who hold traditional religious views on sin and proper behavior to do their own heavy lifting instead of using the State to do it for them then you can't outlaw traditional methods of religious moral expression. The Church used to be in charge of domestic relations law, blasphemy, Sabbath keeping, etc. There's no reason that the churches couldn't do it again. I think that the takeover of such areas of law by the nation state during its growth phase was very unfortunate.
But if they are to do so you can't outlaw actions by believers designed to discourage sin which don't initiate force. You can't outlaw picketing of abortion clinics. You can't outlaw positive discrimination in favor of the righteous (the Christian Yellow Pages), economic boycotts of heathens or sinners, and a patriarchal family organization.
So out go antidiscrimination laws (which are major human rights violations in any case). Believers must be free to fire heathens or sinners, refuse to hire them, refuse to rent to them, etc. Picketing can't be punished with RICO suits. Churches must be allowed to defend their buildings and communities from attacks by their enemies. Thus communists or other leftists who attack churches must be held as "outlawed" (unprotected by civil law) while they are on church property. Churches and their members must be able to recognize only marriages which meet their standards and discriminate against those not meeting those standards. Since disfellowship will be their major means of moral promotion, churches and their followers must be allowed to discriminate economically against the heathen and they must be able to forcefully exclude the heathen from their religious services and properties. An independent legal regime of sorts. That status for religious properties has a lot of traditional support.
You must also either end Public Education, or at least compulsory education, or allow believers trapped in that unfortunate system to protect their children from the godless atheistic communism of educators. They must be able to exempt their children from sex education, earth-worship, secular ethics, and much of the rest of the curriculum. Unregulated private schooling and home schooling must be explicitly legalized.
The State can't both fail to protect the rights of traditionalists to lead traditional lives and at the same time prevent them from themselves protecting their right to lead traditional lives.